Primary sarcomas of the salivary glands: case series and literature review

Primary leiomyosarcoma of the parotid gland: Aspiration cytology with emphasis on differential diagnosis

Most salivary gland neoplasms are of epithelial origin. Sarcomas of the parotid gland, including leiomyosarcoma, are exceedingly rare mesenchymal tumours. A definitive diagnosis of leiomyosarcoma is challenging on cytomorphology alone. We herein describe a case of a 41-year-old woman who presented with parotid gland swelling. The patient was previously diagnosed with leiomyosarcoma of the parotid gland on histopathology. Fine needle aspiration cytology was done from this recurrent swelling. Cytomorphology combined with cell block immunocytochemistry was fruitful in confirming the tumour recurrence. Primary and recurrent/metastatic leiomyosarcoma of the parotid gland is a rarity and cannot be distinguished on cytology. Such a distinction is based on the known history of prior malignancy, which was forthcoming in the present case, or after an exhaustive work-up. Pertinent clinical history and radiology provide leads for the cytopathologist. They must be sought so that immunocytochemistry can be applied judiciously and a precise/nearly precise cytological diagnosis rendered, as it guides patient management. The diagnosis is challenging on cytology as the spindle cell lesions of the parotid gland range from reactive to benign to malignant tumours.

Epithelioid Hemangioendothelioma with WWTR1-CAMTA1 Fusion in the Parotid Gland Presenting as Bell’s Palsy

Epithelioid hemangioendothelioma is a rare tumor of endothelial differentiation most commonly arising in soft tissue, liver, and lung, following a variable clinical course. Most cases are characterized by a t(1;3)(p36;q23-25) resulting in WWTR1-CAMTA1 fusion. Only five epithelioid hemangioendothelioma have been previously reported arising in the salivary glands. None have presented as Bell’s palsy. In the current case, a 37-year-old female presented with a longstanding complaint of pain and fullness in the right preauricular region and progressive episodes of Bell’s palsy and facial nerve weakness. Surgical resection showed a tumor comprised of atypical cells with occasional intracytoplasmic vacuoles in a fibromyxoid stroma. Immunohistochemical stains demonstrated the neoplastic cells expressed ERG, CD31, and CD34, confirming vascular differentiation. Fluorescence in situ hybridization revealed a t(1;3)(p36;q25), confirming a diagnosis of epithelioid hemangioendothelioma. At 12-month follow-up, the patient has no evidence of disease.

Mesenchymal neoplasms of the parotid gland and parapharyngeal space: an FNA cytologic study of 22 nonlipomatous tumors

BACKGROUND

Mesenchymal neoplasms of the parotid gland (PG) and para-pharyngeal (PP) space are distinctly uncommon. Fine-needle aspiration (FNA) biopsy experience with nonlipomatous neoplasms from this site is reviewed.

METHODS

Cytopathology and surgical pathology files were examined for mesenchymal PG and PP space neoplasms. FNA biopsy was performed using standard technique.

RESULTS

Twenty-two PG and/or PP aspirates from 20 adults (male:female = 1.1:1; age range, 19-84 years, mean age, 50 years) and a 10-week-old infant met inclusion criteria. Biopsy sites included PG (17, 77%) or PP space (5, 23%). Five of 6 malignant neoplasms (83%) were called malignant cytologically. Only 7 of 11 (63%) benign neoplasms were recognized as a benign neoplasm. None of 5 solitary fibrous tumor (SFT) cases were correctly recognized. Conversion to the Milan classification showed 8 (36%) FNA cases diagnosed as benign neoplasm, 6 (27%) malignant neoplasm, 4 (18%) neoplasm of uncertain malignant potential, 2 (9%) nondiagnostic, and single cases of suspicious for malignancy and nonneoplastic. There was 1 false-positive and no false-negative FNA diagnoses. Ancillary testing in 10 (45%) aspirates helped substantiate a correct specific diagnosis in 3 malignant and 3 benign cases.

CONCLUSIONS

FNA biopsy of nonlipomatous mesenchymal SG neoplasms is particularly challenging. Less than half (9 of 11, 41%) had specific FNA diagnoses that correctly matched the tissue diagnoses or clinical outcome. Accurate Milan categorization was superior for malignant neoplasms (5 of 6, 83%) in contrast to benign neoplasms (7 of 11, 63%), or neoplasms of uncertain malignant potential (SFT) (2 of 5, 40%).

Soft tissue head and neck sarcoma: experience of a tertiary referral centre over a 15-year period

BACKGROUND

Head and neck soft tissue sarcoma is uncommon. It is both histologically and clinically heterogeneous, ranging from an indolent, locally destructive tumour, to a locally aggressive neoplasm with metastatic potential.

METHODS

A retrospective review was conducted of all adult head and neck soft tissue sarcomas, including cases of malignant soft tissue sarcoma and all intermediate type tumours, diagnosed between 1997 and 2012.

RESULTS

Sixty-eight cases were identified in this series from the sarcoma multidisciplinary team. Seventeen different histological subtypes of sarcoma were identified. Neither age, gender nor tumour size were significant prognostic indicators for survival in this series.

CONCLUSION

Prognosis is dependent on histological subtype, underscoring the importance of histological classification. Some histological subtypes occur only once or twice in a decade, even within a large regional referral centre. An accumulation of evidence from relatively small case series is key in the long-term development of treatment strategies.

Primary unclassified sarcoma of the parotid gland: a case of diagnostic and therapeutic challenge

Malignant salivary gland sarcomas represent a clinically and histologically diagnostic challenge. Primary unclassified sarcomas of the parotid gland consist a rare salivary gland tumor. We report an unusual case of such a tumor, which occurred in the right parotid gland of a 54-year-old male and presented as an asymptomatic painless mass. The pathologoanatomical examination revealed a rhabdoid large-cell unclassified sarcoma. The patient was treated with superficial parotidectomy and adjuvant radiotherapy. No recurrence was noted in a 10-year follow-up period. Due to the rare occurrence of primary unclassified sarcomas, there is no evidence-based treatment of choice. An optimal approach is best planned in a multidisciplinary setting, taking into consideration the resectability of the tumor, individual patient characteristics, presence of local or distant metastatic activity, local infiltrative behavior and tumor stage. A close follow-up of the patient is strongly recommended.

Adamantinoma-like Ewing sarcoma mimicking basal cell adenocarcinoma of the parotid gland: a case report and review of the literature

Adamantinoma-like Ewing sarcoma (AES) is a rare variant of the Ewing family of tumors that resembles classic adamantinoma of bone. AES shows epithelial differentiation and a more complex immunohistochemical expression profile with keratin and basal marker immunoreactivity and can resemble a variety of carcinomas. We report an unusual case of an AES of the parotid gland that mimicked a basal cell adenocarcinoma. Like basal cell adenocarcinoma, this AES showed a nested basaloid proliferation with peripheral palisading in tumor nests with 'basaloid' epithelial differentiation as highlighted by cytokeratin AE1/3 and p40 positivity. However, unlike most basal cell adenocarcinomas, this tumor demonstrated high grade morphology, showed no true ductal or myoepithelial component, and also showed a tendency towards neuroectodermal phenotype with focal rosette formation, CD99 and weak synaptophysin immunoreactivity. EWSR1 and FLI1 fluorescence in situ hybridization confirmed the presence of a translocation supporting the diagnosis of AES. This is the first case of AES presenting as a primary parotid mass highlighting the potential to be mistaken for primary salivary gland carcinomas, which in addition to basal cell adenocarcinoma include other basaloid tumors such as adenoid cystic carcinoma.

Sclerosing rhabdomyosarcoma: presentation of a rare sarcoma mimicking myoepithelial carcinoma of the parotid gland and review of the literature

Sclerosing rhabdomyosarcoma (SRMS), a recently characterized variant of rhabdomyosarcoma, can pose a significant diagnostic challenge given its rarity and its histological similarity to other malignancies. SRMS is characterized by dense hyalinized or sclerosing collagenous matrix and a pseudovascular pattern of growth. SRMS shares histologic similarities with several mesenchymal tumors including: leiomyosarcoma, osteosarcoma, chondrosarcoma, angiosarcoma, and sclerosing epithelioid fibrosarcoma. We herein report a case of SRMS mimicking a myoepithelial carcinoma of the parotid gland. The tumor contained small, spindled, and epithelioid tumor cells lining pseudovascular spaces within a dense hyalinized stroma. Initial stains for keratins, S100 and p63 were negative. However the tumor cells showed desmin and myogenin positivity. The tumor was negative for FKHR gene rearrangements and showed no MDM2 gene amplification. This is the second case of SRMS to be diagnosed in the parotid gland highlighting the potential for misdiagnosis as a primary salivary gland epithelial malignancy.